18938623 has 4 divisors (see below), whose sum is σ = 20660328. Its totient is φ = 17216920.

The previous prime is 18938617. The next prime is 18938639. The reversal of 18938623 is 32683981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32683981 = 11 ⋅2971271.

It is a cyclic number.

It is not a de Polignac number, because 18938623 - 2²¹ = 16841471 is a prime.

It is a super-2 number, since 2×18938623² = 717342882272258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18938123) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 860836 + ... + 860857.

It is an arithmetic number, because the mean of its divisors is an integer number (5165082).

Almost surely, 2^18938623 is an apocalyptic number.

18938623 is a deficient number, since it is larger than the sum of its proper divisors (1721705).

18938623 is a wasteful number, since it uses less digits than its factorization.

18938623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1721704.

The product of its digits is 62208, while the sum is 40.

The square root of 18938623 is about 4351.8528237982. The cubic root of 18938623 is about 266.5525242404.

The spelling of 18938623 in words is "eighteen million, nine hundred thirty-eight thousand, six hundred twenty-three".